Thursday, April 21, 2011

Kenwood KT-6040 back online in left side pile

The new re-arrangement of equipment is coming together. (The inspiration, from a few posts back, was that no stack of equipment should be higher than seated lap level, to avoid interfering with the dipolar sound field of the Acoustats.)

Sony 507 ESD CD player, a classic from 1989, but mainly used for guest CD's because I don't like putting potentially dirty discs into my premium universal disc players. I will use the coax digital output (not connected yet). This player has excellent error correction, better than some universal disc players, as I discovered last year. I dug out the 507, and sure enough it played a terribly scratched disc flawlessly.

Used a nice looking premium Radio Shack 75ohm video for the digital connection.

9 foot RG-6 for connecting to twinlead dipole antenna on other side of room. F-to-Euro adapter.

Used nylon tie wraps to coil up AC cords for neatness and to avoid proximity problems.

Just the wiring part of the setup took about 2 hours and lots of kneeling gymnastics. non-Audiophiles will probably never appreciate what hard work this is.

When first hooked up, I was amazed by the transparency. Perhaps PAD-1 digitizer is as good or better than Lavry AD10, I initially thought. Then I noticed the lack of bass. I hadn't re-powered subs or supertweeters. Re-powering them robbed a slight bit of the unreal transparency but gave much more warmth and reality. My ultimate guess was that the Lavry is still slightly better, but the PAD-1 is very close.

Unfortunately, the music on my 3 favorite stations was a bit lame at 4am.

I'm glad I can now switch over to Oppo disk player using remote control, because Oppo uses a separate digitizer (the Lavry) and they both feed digital to the Tact.

One problem with this setup is that the PAD-1 only works well through it's balanced inputs. (Through balanced inputs, the distortion measures 0.001%, almost at my residual, but through the single ended inputs, distortion measures 0.01%.) The balanced inputs are set up for 10V RMS input. So by using the balanced inputs, but without a preamp, I may be loosing as much as 12dB of potential dynamic range. But I don't see anywhere in the existing setup I can place of my Acurus L10 or Aragon 28k preamps to boost the level 6dB or so. Perhaps I could build new line amplifier inside the MSB itself (replacing whatever junk they have in there now), or in a smallish box. Or find something small but high quality.

Using the Lavry elides this problem because the Lavry has a 13dB gain adjustment range with handy peak holding LED meters.

Anyway, the loss of dynamic range is probably not much to worry about for FM. Even with 12dB loss, I still have 100dB or so in the digitizer, whereas FM stations are more in the range of 50-60dB with my current antenna. I need to improve antenna! Actually, you can't push FM level too close to the max anyway, you need lots of headroom to avoid clipping while tuning in stations.